Agree completely - your complaint is not justified. Sure, you might be disappointed that the hotel didn't go above and beyond, but this is not grounds for a customer service complaint. If you wanted something special, you should have arranged (and paid for it) yourself.
I am a Platinum member with an Ambassador and recently stayed in a hotel in London on my boyfriend's birthday. I left a note with the hotel and asked my Ambassador to mention my boyfriend's birthday to the hotel as well but did not receive anything special. It would have been nice had the hotel provided something, but it is not a big deal and I certainly didn't complain to corporate about it -- as I wasn't relying on the hotel to do anything special.